Turbos face overboosted efficiency claims

Originally published: February 21, 2013

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There’s been tough news for automakers looking to boost their corporate average fuel economy in the wake of increasingly stringent government-mandated fleet averages. First came the Consumer Reports magazine report that many of the small turbocharged engines introduced in recent years to increase fuel economy without sacrificing performance are failing to perform, sometimes on both fronts.

According to the consumer watchdog, an entire slew of supposedly more efficient small turbos are failing to deliver fuel economy gains over the larger four- and six-cylinder engines they are supposed to replace. Except for the 2.0-litre four-cylinder engine that powers the latest BMW 328 and the 1.4L Dodge Dart, Consumer Reports notes that all the turbocharged engines it has tested feature worse fuel economy and/or poorer performance than their direct competitors.

“While these engines may look better on paper with impressive EPA numbers, in reality, they are often slower and less fuel-efficient than larger four- and six-cylinder engines,” said Jake Fisher, director of automotive testing for Consumer Reports.

So, while the Ford Fusion 1.6-litre EcoBoost promises 28 (U.S.) miles per gallon in EPA testing, the magazine found it only delivered 25 mpg. Its conventional competition – 2.4L Toyotas, Hondas and Nissans – all delivered superior real-world figures while accelerating significantly faster to 60 miles per hour (96 km/h).

The scenario repeated itself when the magazine compared the Titanium version of the Ford Fusion – powered by a 2.0L turbocharged EcoBoost – with the 3.5L V6 Honda Accord, Toyota Camry and Nissan Altima. Though its EPA (U.S.) 26 mpg figure was superior, its real-world fuel economy was inferior to V6 counterparts (at 22 U.S. mpg, it trailed by 4, 4 and 2 U.S. mpg respectively) and the turbocharged Ford was slower to boot. It’s also worth noting that Kia’s similarly turbocharged Optima also was also two U.S. mpg arrears of the V6-powered Camry and Accord, while Hyundai Sonata only trailed by one U.S. mpg. All three turbocharged cars were, however, slower than the V6s

Ford’s 1.6L EcoBoost-powered Escape also used more fuel than the 2.4L Honda CR-V and the 2.5L Toyota RAV4. Chevrolet’s 1.4L Cruze ECO at least matched its 1.8L naturally aspirated standard engine in real-world testing (though its as-tested 26 U.S. mpg economy was 2 mpg lower than its EPA rating). The turbocharged Cruze ECO was also significantly quicker.

It all points to, as Post Driving has also noted, flaws in the testing systems that seem to favour turbocharged engines over their conventional counterparts. Indeed, the most consistent trend in Consumer Reports testing is that the turbocharged engines’ real–world economy were always lower than their EPA ratings while their conventional counterparts’ on-the-road economy was often higher than the EPA claimed. Indeed, because of the way turbocharged engines are supposed to save fuel – essentially the manufacturer significantly reduces the displacement of its engines and then turbocharges them so that they can develop full-sized power when called upon – they are quite effective during laboratory testing under low-throttle steady-state conditions. But, as soon as a heavier foot is applied, their force-fed induction quickly ramps up consumption.

In other fuel consumption news, Reuters noted in a report on Feb. 4 that electric cars may be heading toward another dead end. “Recent moves,” says the article’s authors, “by Japan’s two largest automakers suggest that the electric car, after more than 100 years of development and several brief revivals, still is not ready for prime time – and may never be.”

EVs are still compromised by some of the same problems that plagued them 100 years ago – “high cost, short driving range and lack of charging stations” – the authors say, noting many institutions are already backing away from heady promises made just a few short years ago. The Obama administration recently dumped its goal to have one million electric vehicles on American roads by 2015, the authors say, and even Carlos Ghosn, CEO of Nissan, who had hitherto pushed pure EVs as the only solution to automotive emissions, has recently announced a shift toward more conventional gasoline/electric hybrids.

The issue has far-reaching consequences for automakers looking to find ways to attain the 54.5 U.S. mpg standards required by 2025. Electric vehicles, along with other favoured alternative technologies, are given special credits in the standards and many automakers are relying on them to get their corporate fleet fuel economy averages up to standard. One thing both reports illustrate is the growing schism between what the manufacturers need to do to appease government fuel economy regulations and what actually achieves superior fuel consumption in the real world.

There was a sliver of good news in the Reuters report. Because of the seeming lack of interest in pure electric cars, some automakers may be reviving their dormant hydrogen fuel-cell programs, previously sidelined when they thought that EVs would be the dominant alternative to the internal combustion engine.